What exactly is pain-free rehabilitation? Many patients with knee injuries or post-operative stiffness experience a very painful period, such as when many rehabilitators will perform a straightforward leg break on a patient who feels a lot of pain. In fact, painless rehabilitation techniques are now being used more and more widely and can help patients fully regain knee motion without pain. It has developed through three main stages. Stage 1: Traditional stage. Before the patient recovers or after surgery, pain medication is dispensed or pain cream is applied to the affected area, which is less effective. Stage 2: General anesthesia technique. Patients are given overall anesthesia, and rehabilitation is performed in a state of unconsciousness and muscle relaxation to obtain a better loosening effect, but rebound is easily performed after surgery. Stage 3: Using painless rehabilitation techniques. Using the latest local nerve tissue technology, only the injured area is anesthetized and the anesthetic effect lasts for 6-8 hours. After restoring the movement of this joint, painless rehabilitation technology can help the patient to continue the rehabilitation and maintain the rehabilitation angle to achieve good results. Painless rehabilitation can help patients return to their original state. Who is suitable for painless rehabilitation techniques? Category 1: Activity limitation. Patients who have reached a bottleneck in their rehabilitation through conventional rehabilitation techniques and whose angles cannot be further improved. Category 2: In terms of post-operative time, the appropriate time is three to six months. At this time, the scar is not too strong and our normal soft tissue tolerance level is sufficient. Painless rehabilitation can be performed. Category 3: To have no significant knee extension device injury. There are many people who are subjected to violent leg breaking and already have a quadriceps strain, or patellar tendon injury prior to treatment, and this is the time to rest and condition first. Conversely, this tissue damage can be exacerbated. The above three types and situations are suitable for painless rehabilitation techniques. However, it is important to note that an orthopedic surgeon and a rehabilitation therapist need to evaluate the patient before pain-free rehabilitation techniques are actually performed to ensure that nothing is lost.